This invention relates to improvements in fuel cell adapter systems for use in combustion tools. As exemplified in Nikolich U.S. Pat. Nos. 4,403,722, 4,483,474, 4,522,162, and 5,115,944, all of which are incorporated by reference, it is known to use a dispenser to dispense a hydrocarbon fuel to a combustion gas-powered tool, such as, for example, a combustion gas-powered fastener-driving tool. Such fastener-driving tools and such fuel cells are available commercially from ITW-Paslode (a division of Illinois Tool Works, Inc.) of Vernon Hills, Ill., under its IMPULSE trademark. In particular, a suitable fuel cell is described in Nikolich U.S. Pat. No. 5,115,944, listed above.
A standard system for attaching a fuel cell to a combustion tool is known, i.e. placing the fuel cell into the combustion tool with a metering unit, and having no adapter. This system has the advantage of being compact, however it does not protect the female metering unit inlet from dirt and other debris. Also, when not using an adapter, a protective cap or blister pack is needed for transporting the fuel cell.
There is another known fuel cell attachment system for combustion tools, where a seal support attaches to a fuel cell and creates a seal for joining the fuel cell stem and a male joiner from the combustion tool. However, this adapter system does not protect the fuel cell from dirt and other debris. Another disadvantage is that the presence of this adapter alone is believed to diminish the life and capacity of the fuel cell. Still another unwanted characteristic of this adapter is that it can be removed from its current fuel cell and reused with a generic fuel cell.
One disadvantage of conventional combustion tool fuel cells is that the conventional alignment structures employed for aligning the corresponding stems or passageways of the fuel cell and the tool fuel metering valve do not provide consistent coaxial alignment of these passageways, which may lead to wasted fuel, shortened fuel cell life and less than optimal tool performance.
Another disadvantage of conventional combustion tool fuel cells is that in some cases, users may be tempted to refill spent fuel cells with generic fuel. This may impair the operation of the tool. Thus, there is a need for an adapter for a combustion tool fuel cell which is configured to discourage refilling.
Accordingly, one object of the present invention is to provide an improved fuel cell attachment system that protects the fuel cell from dirt and other debris while in use.
Another object is to provide an improved fuel cell adapter that protects the fuel cell stem during transportation, thus eliminating the need for a protective cap or blister pack.
A further object is to provide an improved fuel cell adapter that is able to provide visual identification of whether the fuel cell is unused or not.
Yet another object of the present invention is to provide an improved combustion tool featuring a latch inside the combustion tool that releasably holds the fuel cell in an engaged position.
Still another object of the present invention is to provide an improved adapter for a fuel cell that cannot be removed from a fuel cell and reused with a generic fuel cell.
A still further object of the present invention is to provide an improved adapter for a fuel cell which inhibits refilling of existing spent fuel cells.
One more object of the present invention is to provide an improved locking system for a tool which lockingly receives the fuel cell adapter and releasably locks the adapter in proper operational position within the tool.
The above-listed objects are met or exceeded by the present fuel cell adapter system for a combustion tool which features an adapter having a frangible membrane on its free end to protect the fuel cell during transportation, a gripping formation configured for engagement with a latch, and a latching feature inside the combustion tool which releasably secures the fuel cell in engagement with the internal tool fuel metering valve. The present latching feature keeps the whole system compact in size and facilitates installation and removal of the fuel cell. In addition, lobes on the front surface of the adapter are configured to align the mating fuel metering stem axially with the fuel cell housing. Another feature of the present fuel cell adapter for a combustion tool is an enlarged base which, when mechanically compressed, fits inside the rim of the fuel cell housing to form a fixed attachment between the fuel cell adapter and the fuel cell housing. An additional feature of the present invention is a set of breakable ribs which undergo shear failure upon attempted removal of the fuel cell adaptor from the fuel cell housing.
In addition to protecting the fuel cell during transportation, the present adapter system also protects the fuel cell from dirt and debris while in use with the combustion tool. The lobes located on the front surface of the fuel cell adapter prevent a wholly flush contact surface between the front surface of the fuel cell adapter and the surface of the fuel cell to enable the removal of dirt, debris, and other impurities from the location of engagement. Further, the frangible membrane on the adapter visually indicates whether the fuel cell is unused.
Another advantage of the present invention is that, if an attempt is made to remove the present adapter from the fuel cell, the connecting ribs of the fuel cell adapter undergo shear failure, causing the nose portion of the fuel cell adapter to become separated or otherwise structurally weakened from the base portion of the fuel cell adapter, which remains mechanically fastened to the fuel cell. Upon shear failure of the ribs, the fuel cell adapter cannot be reused on another fuel cell. This feature reduces the chance for the introduction of dirt, debris, or impurities that can interfere with the connection during reuse.
Another feature of the present system is a locking mechanism on the tool which receives the adapter and releasably locks it in place in the proper operational position. Once the fuel cell is empty, in the preferred embodiment, the user merely rotates the fuel cell to overcome the locking force, and easily pulls the fuel cell from the tool.
More specifically, the present invention provides a fuel cell adapter configured for connection to a fuel cell which is engageable upon a fuel metering valve of a combustion tool including an adapter body having a base configured for engagement upon the fuel cell and a nozzle connected to the base, the nozzle having a lobed free end configured for facilitating engagement upon the valve.
The present invention also provides an enlarged base which attaches the fuel cell adapter to the rim of the fuel cell can. When the fuel cell adapter is mechanically pressed to fit into the fuel cell can, a peripheral wedge on the base of the fuel cell adapter mates with a lip on the underside of the rolled seam located on the inside diameter of the fuel cell can.
Another embodiment of the present invention is a fuel cell adapter configured for connection to a fuel cell, including an adapter body having a generally cylindrical nozzle and a base configured for engagement upon the fuel cell, with the nozzle being connected to the base. The adapter body also has a gripping formation configured for engagement with a latch.
The nozzle has a plurality of lugs, a plurality of lobes, and a plurality of support ribs. Each lug has a ramped configuration, extending from the free end toward the base, and has a truncated lug end. The plurality of lobes are chamfered to guide the mating adapter and fuel cell into axial alignment. The support ribs each have a truncated rib end and are configured for connecting the nozzle to the base.
The present invention further provides a combustion tool including a housing which encloses a fuel metering valve and a fuel cell provided with an adapter configured for being accommodated in the housing for fluid communication with the metering valve. A latch is disposed in the housing for releasably securing the adapter in fluid communication with the metering valve. The latch includes a latch body having at least one locking tang movable between a closed position and an open position. There is also a release member for moving the locking tang to release the engagement with the adapter and permitting withdrawal of the fuel cell from the tool.